Search Results (181)

Nephrotic syndrome (NS) is characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia. Apart from the traditional causes of NS, such as minimal change disease, focal segmental glomerulosclerosis, diabetes, infections, malignancies, autoimmune conditions, and nephrotoxic agents, there are also rare causes of NS, whose knowledge is of the utmost importance. The aim of this article was to highlight the less well-known causes that have a significant impact on diagnosis and treatment. Genetic syndromes such as Schimke immuno-osseous dysplasia, familial lecithin-cholesterol acyltransferase deficiency with two clinical variants (fish-eye Disease and the p.Leu364Pro mutation), lead to NS through mechanisms involving podocyte and lipid metabolism dysfunction. Congenital disorders of glycosylation and Nail–Patella Syndrome emphasize the role of deranged protein processing and transcriptional regulation in glomerular injury. The link of NS with type 1 diabetes, though rare, suggests an etiology on the basis of common HLA loci and immune dysregulation. Histopathological analysis, particularly electron microscopy, shows mainly podocyte damage, mesangial sclerosis, and alteration of the basement membrane, which aids in differentiating rare forms. Prompt recognition of these novel etiologies by genetic analysis, renal biopsy, and an interdisciplinary panel is essential to avoid delays in diagnosis and tailored treatment. Full article

Focal and segmental glomerulosclerosis (FSGS) describes a histological pattern of injury seen by light microscopy in kidney biopsy specimens and is the end result of various injuries to the podocyte. Our understanding of this disease entity has evolved greatly since it was first described, with particular focus on changes in the classification of FSGS as a disease entity and expansion in our understanding of the underlying pathophysiology. The incidence and prevalence of FSGS and FSGS-associated end-stage kidney disease (ESKD) have increased globally, particularly in the United States; it is now the most common primary glomerular disorder in those with ESKD. APOL-1 is likely responsible for this epidemiological trend in kidney disease in the US and is an important focus of clinical trials and potential targeted therapies. Currently, the goal of treatment in FSGS is to achieve remission of proteinuria and to prevent progression to ESKD. Remission is achieved by using immunosuppressive therapies in primary FSGS, but treatment in secondary and genetic FSGS is largely supportive. Recurrent FSGS (rFSGS) post-transplantation remains a significant clinical challenge to nephrologists; current monitoring and treatment strategies are based on retrospective meta-analysis and observational studies with no clear consensus as to the optimum approach. Emerging therapies are focused on developing more targeted interventions in genetic and secondary FSGS. This review article aims to comprehensively explore this multifaceted disease entity. Full article

Diabetic nephropathy (DN) represents a severe microvascular complication of diabetes mellitus. As a Traditional Chinese Medicine (TCM) with extensive clinical applications, Ligustri Lucidi Fructus (LLF) exhibits significant anti-DN activity. However, the underlying pharmacological mechanisms, crucial components, and targets for LLF in DN treatment remain unclear. By integrating network pharmacology, molecular docking, and molecular dynamics simulations, the bioactive compounds, potential therapeutic targets, and underlying mechanisms of LLF in the treatment of DN were elucidated, followed by biological validation in a palmitic acid (PA)-induced MPC5 podocyte injury model. Among the 383 DN-related LLF targets identified, TNF emerged as a pivotal one, demonstrating potential binding interaction with the active components salidroside (Sal), apigenin (Api), and tormentic acid (TA). Moreover, Gene Expression Omnibus (GEO) database and KEGG enrichment analysis collectively highlighted the cytosolic DNA-sensing pathway. Notably, the cGAS-STING pathway is central to this pathway. Experimental studies further demonstrated that LLF-containing serum exerted a protective effect on MPC5 podocytes through cGAS-STING pathway suppression. Overall, these findings elucidate the pleiotropic mechanisms underlying LLF’s protective effects against DN, integrating compound–target–pathway interactions and thus offering a rationale for further investigation. Full article

Obesity, hypertension, and chronic kidney disease (CKD) constitute the deadly trinity of modern threats for populations of both developed and developing countries. These diseases (together with type 2 diabetes) are closely linked in their pathophysiology and result in increasing cardiovascular (CV) morbidity and premature death from CV causes. In this review, we focused on the kidney as the target of obesity-related disorders. Obesity-related glomerulosclerosis (ORG) represents a pattern of renal injury caused solely or predominantly by obesity; usually, it is superimposed on chronic kidney disease (CKD) from other causes, such as diabetic kidney disease, hypertensive kidney disease, type 2 cardiorenal syndrome, primary or secondary glomerulopathies, and others. Adipose tissue contributes to kidney injury in several ways: it releases proinflammatory cytokines and growth factors, leading to podocyte and mesangial cell injury and glomerulosclerosis. In particular, perirenal adipose tissue (PRAT), besides exerting paracrine and endocrine effects on the kidney, modifies its function via compression on renal parenchyma and vessels. The intrinsic ability of the kidneys in obesity to increase the reabsorption of sodium warrants intraglomerular hypertension and hyperfiltration, followed by progressive renal injury. Lifestyle interventions and pharmacological agents, as well as metabolic (bariatric) surgery resulting in weight reduction, may also be beneficial for the kidneys. Using GLP1 receptor agonists (with a special focus on subcutaneous semaglutide and tirzepatide) seems to be the most promising treatment strategy for preventing kidney injury in obese individuals. Full article

SHROOM3 encodes an actin-binding protein involved in kidney development and has been associated with chronic kidney disease through genome-wide association studies. However, its regulatory role in proteinuric kidney diseases and its mechanistic contributions to podocyte homeostasis remain poorly defined. Here, we analyzed single-cell transcriptomic datasets and the Nephroseq database to delineate SHROOM3 expression patterns in proteinuric kidney diseases. Using podocyte-specific SHROOM3 knockout mice and an Adriamycin (ADR)-induced nephropathy mouse model, we demonstrated that glomerular SHROOM3, specifically in podocytes, was upregulated following ADR treatment during the acute injury phase but downregulated in chronic kidney disease. Clinically, the glomerular SHROOM3 expression positively correlated with glomerular filtration rates in focal segmental glomerulosclerosis patients. Genetic ablation of SHROOM3 in podocytes exacerbated ADR-induced proteinuria, diminished podocyte markers (nephrin, podocin, and WT1), and accelerated glomerulosclerosis. In vitro, SHROOM3 deficiency impaired podocyte size and adhesion, concomitant with the downregulation of focal adhesion molecules (talin1, vinculin, and paxillin) and stress fiber regulators (synaptopodin and RhoA), as well as calpain activation and RhoA inactivation. Our findings reveal a critical role for SHROOM3 in maintaining podocyte integrity and suggest its therapeutic potential in mitigating proteinuric kidney disease progression. Full article

Background/Objectives: Fabry nephropathy (FN) is a progressive complication of Fabry disease that significantly affects patient outcomes. However, the molecular mechanisms underlying FN are not yet fully understood. Recent advances in transcriptomics have opened new perspectives for the identification of early changes in gene expression associated with the development and progression of the disease. Methods: This study includes a systematic review of transcriptomic findings in chronic kidney disease, with a particular focus on FN, and presents a proof-of-concept RNA sequencing analysis of peripheral blood samples from six Fabry patients with progressive nephropathy and six age- and sex-matched control subjects. Results: The analysis identified 41 differentially expressed genes (DEGs), all of which were upregulated in Fabry patients. Enrichment analysis revealed significant involvement in immune-related pathways, including neutrophil degranulation, interferon, and cytokine signaling. Cell type enrichment revealed that neutrophils and other immune cells are key players in this process. Conclusions: These results suggest that immune and inflammatory mechanisms play a central role in the pathogenesis of FN. The identified DEGs are involved in pro-fibrotic signaling and immune system activation and shed light on possible mechanisms underlying fibrosis, podocyte injury, and kidney damage. This study contributes to a deeper understanding of FN and may facilitate in the identification of early biomarkers for diagnosis and disease monitoring. Full article

Hypertension and diabetes are two common causes of chronic kidney disease. Hypertension can induce renal vascular injury, glomerular damage, podocyte loss, and tubular injury, leading to tubulointerstitial fibrosis. A number of factors influence the regulation of hypertension, among which G-protein-coupled receptors (GPCRs) have been studied extensively because they are desirable targets for drug development. Compared to hypertension, the regulatory effects of GPCRs on hypertensive kidney disease (HKD) are less generalized. In this review, we discussed the GPCRs involved in hypertensive kidney disease, such as angiotensin II receptors (AT1R and AT2R), Mas receptor (MasR), Mas-related G-protein-coupled receptor member D (MrgD), relaxin family receptor 1 (RXFP1), adenosine receptors (A₁, A_2A, A_2B, and A₃), purinergic P2Y receptors, and endothelin receptors (ET_A and ET_B). The progression of HKD is rarely reversed but can be retarded by ameliorating the hypertensive microenvironment in the kidneys. However, simply reducing blood pressure cannot stop the progression of HKD. Diabetic nephropathy (DN) is the most common cause of end-stage renal disease (ESRD), which is a major cause of morbidity and mortality in diabetes. Many GPCRs are involved in DN. Here, we select some well-studied GPCRs that are directly associated with the pathogenesis of DN to illustrate their mechanisms. The main purpose of this review is to provide an overview of the GPCRs involved in the occurrence and progression of HKD and DN and their probable pathophysiological mechanisms, which we hope will help in developing new therapeutic strategies. Full article

Background: Podocytes are essential for kidney function, and their dysfunction can result in nephrotic syndrome, such as minimal change disease (MCD). Oxidative stress contributes to podocyte damage. We investigated the therapeutic potential of intravenously infused mesenchymal stem cells (MSCs) in a puromycin aminonucleoside (PAN)-induced rodent MCD model, focusing on oxidative stress modulation. Methods: Sprague-Dawley rats were divided into three groups: intact, PAN-Vehicle, and PAN-MSC. MCD was induced through subcutaneous PAN injection. MSCs were infused intravenously in the PAN-MSC group on day 7. Urinary albumin, serum albumin, and creatinine levels were assessed. Histological analysis of the renal cortex was performed. Podocyte protein (NPHS1, NPHS2, and PODXL) and antioxidant enzyme (SOD1, SOD2, and GPX1) levels were measured using quantitative real-time reverse-transcription PCR (qRT-PCR). Results: MSC infusion significantly reduced proteinuria and restored podocyte structure in the PAN-MSC group. Electron microscopy revealed that infused MSCs could inhibit the fusion of the foot process induced by PAN injection. qRT-PCR showed that intravenous infusion of MSCs rescued the inhibition of GPX1 expression. GFP-labeled MSCs accumulated at the podocyte injury sites. Conclusion: Systemic MSC infusion mitigates PAN-induced MCD by reducing proteinuria, preserving podocyte structure, and modulating oxidative stress via the GPX1 pathway, offering a potential therapeutic approach for nephrotic syndrome. Full article

Sodium orthovanadate is a non-selective protein tyrosine phosphatase inhibitor that can cause several types of kidney injury, including glomerulosclerosis, inflammation, and tubular damage. Cannabis is widely known for its medicinal use, and several studies have demonstrated its anti-diabetic and anti-inflammatory properties. The current study investigated the therapeutic effect of Lebanese cannabis oil extract (COE) against sodium orthovanadate-induced nephrotoxicity both in vitro and in vivo. Sprague Dawley male rats were intraperitoneally injected with 10 mg/kg sodium orthovanadate for 10 days followed by 5 mg/kg; 10 mg/kg; or 20 mg/kg intraperitoneal injection of cannabis oil extract, starting on day 4 until day 10. The body weight of the rats was monitored during the study, and clinical parameters, including serum urea, creatinine, and electrolytes, as well as kidney and heart pathology, were measured. Conditionally immortalized cultured rat podocytes were exposed to either sodium orthovanadate or selective phosphatase inhibitors, including DUSPi (DUSP1/6 inhibitor) and SF1670 (PTEN inhibitor), in the presence or absence of cannabis oil extract. MTS and an in vitro scratch assay were used to assess podocyte cell viability and migration, respectively. Western blot analysis was used to evaluate the phosphorylation levels of AKT and p38 MAPK. Rats injected with sodium orthovanadate displayed a marked reduction in body weight and an increase in serum creatinine and urea in comparison to the control non-treated group. All doses of COE caused a significant decrease in serum urea, with a significant decrease in serum creatinine observed at a dose of 20 mg/kg. Moreover, the COE treatment of rats injected with orthovanadate (20 mg/kg) showed a marked reduction in renal vascular dilatation, scattered foci of acute tubular necrosis, and numerous mitoses in tubular cells compared to the sodium orthovanadate-treated group. The cell viability assay revealed that COE reversed cytotoxicity induced by sodium orthovanadate and specific phosphatase inhibitors (DUSPi and SF1670) in rat podocytes. The in vitro scratch assay showed that COE partially restored the migratory capacity of podocytes incubated with DUSPi and SF1670. Time-course and dose-dependent experiments showed that COE (1 μg/mL) induced a significant increase in phospho-(S473)-AKT, along with a decrease in phospho (T180 + Y182) P38 levels. The current results demonstrated that Lebanese cannabis oil possesses important kidney protective effects against sodium orthovanadate-induced renal injury. Full article

Podocyte injury is a hallmark of both focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD), ultimately reflected in foot process effacement and proteinuria. Triggers and pathogenic pathways leading to podocyte cytoskeleton rearrangements are, however, incompletely explained. Here, we aimed to contribute to the understanding of these pathways using tissue bottom-up proteomic profiling of laser-capture microdissected glomeruli from MCD and FSGS. Forty-six differentially expressed proteins were identified between the two groups (p < 0.05, |FC| ≥ 1.2). Pathway analysis showed that 16 out of 46 proteins were associated with the immune system, with E2 ubiquitin-conjugating enzyme (UBE2K) and complement factor H-related protein-1 (CFHR1) yielding the highest fold change in FSGS compared to MCD. The two target proteins were further validated through immunohistochemistry, confirming the podocyte localization of UBE2K and endothelial staining of CFHR. Additionally, several other differentially expressed proteins were linked to the cytoskeleton structure and its regulation. Our results point to the possibility that complement dysregulation may be the source of cytoskeleton rearrangement in FSGS. Full article

Background/Objectives: Nephrotic syndrome, a glomerular disease caused by podocyte dysfunction, is characterized by proteinuria, hypoalbuminemia, edema, and hyperlipidemia. Current treatment relies on corticosteroids, which carry the risk of long-term side effects. Physalis angulata has potential as an adjunct therapy for immune-mediated kidney injury. This study aims to evaluate the effects of Physalis angulata extracts on anti-nephrin IgG, IL-4, and podocytopathy through BAFF inhibition in a doxorubicin-induced nephrotic syndrome rat model. Methods: This experimental study involved 36 Sprague–Dawley rats divided into control and treatment groups. The treatment groups received Physalis angulata extract at doses of 500 mg/kgBW, 1500 mg/kgBW, and 2500 mg/kgBW, or in combination with prednisone, alongside a group receiving prednisone monotherapy. Podocytopathy was assessed using proteinuria, nephrin, podocalyxin, and GLEPP-1. Proteinuria was measured using spectrophotometry. Serum BAFF levels, renal IL-4, urinary nephrin, and urinary podocalyxin were analyzed using ELISA. Renal nephrin, renal podocalyxin, GLEPP-1, and BAFF expression were evaluated by immunofluorescence microscopy. The data were analyzed using SPSS 25. Results: The results showed significant reductions in proteinuria, serum BAFF levels, renal BAFF expression, anti-nephrin IgG, IL-4, urinary nephrin, and urinary podocalyxin, along with significant increases in GLEPP-1, renal nephrin, and renal podocalyxin expression, in all treatment groups compared to the nephrotic syndrome control group. The combination of Physalis angulata at 2500 mg/kgBW with prednisone demonstrated the best effects. Conclusions: Physalis angulata shows promise as an adjuvant therapy for nephrotic syndrome by improving podocytopathy through BAFF inhibition. Further research is needed to evaluate its long-term safety, optimize dosing, and explore clinical applications in humans. Full article

Diabetic nephropathy (DN) is one of the key causes of end-stage kidney disease worldwide, especially in developed countries. The classic pathogenic development of DN is characterized by microalbuminuria which would progress to nephrotic-range proteinuria and loss of kidney function. The degree of albuminuria is considered an independent risk factor for all-cause mortality in patients with DN. It is now well established that albuminuria stems from disruptions in podocyte structure and function. Podocytes play a major role in the glomerular filtration barrier. The nephrin protein has been identified as a core component of the slit diaphragm in podocytes, and as such, the downregulation of nephrin expression has been described well in various proteinuric glomerulopathies, including DN. Previous studies have shown that the presence of urinary nephrin potentially signifies an early marker of podocyte injury in DN. More recently, there have been increasing bodies of evidence which suggest that circulating autoantibodies targeting nephrin contributes to the pathogenesis of podocytopathies. However, the functional significance of these circulating autoantibodies in patients with DN is not well understood. In this review, we aim to evaluate the significance of nephrin dysregulation in the pathogenesis of DN based on the current available literature and provide an overview on the application of circulating anti-nephrin autoantibodies in relation to its diagnostic as well as prognostic role in podocytopathies, including DN. Full article

Background/Objectives: The pathogenesis of diabetic kidney disease (DKD) is complex and multifactorial. Because of its complications and reduced number of diagnostic biomarkers, it is important to explore new biomarkers with possible roles in the early diagnosis of DKD. Our study aims to investigate the pattern of previously identified metabolites and their association with biomarkers of endothelial dysfunction, proximal tubule (PT) dysfunction, and podocyte injury. Methods: A total of 110 participants, comprising 20 healthy individuals and 90 patients divided in three groups were enrolled in the study: normoalbuminuria, microalbuminuria, and macroalbuminuria. Untargeted and targeted metabolomic methods were employed to assess urinary and serum biomarkers, as well as indicators of endothelial dysfunction, podocyte damage, and PT dysfunction through ELISA techniques. Results: Our research uncovered specific metabolites that exhibit varying levels across different sub-groups. Notably, glycine serves as a distinguishing factor between group C and the normoalbuminuric group. Furthermore, glycine is correlated with endothelial markers, especially VCAM. We observed a gradual decrease in kynurenic acid levels from group C to group P3; this biomarker also demonstrates an inverse relationship with both p-selectin and VCAM. Additionally, tryptophan levels decline progressively from group C to group P3, accompanied by a negative correlation with p-selectin and VCAM. Urinary tiglylglycine also differentiates among the patient groups, with concentrations decreasing as the condition worsens. It shows a strong positive correlation with nephrin, podocalyxin, KIM1, and NAG. Conclusions: In conclusion, glycine, tiglylglycine, kynurenic acid and tryptophan may be considered putative biomarkers for early diagnosis of DKD and T2DM progression. Full article

Podocyte injury plays a central role in both focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD). Pathogenic mechanisms are diverse and incompletely understood, partially overlap between FSGS and MCD, and are not reflected by kidney biopsy. In order to optimize the current variable response to treatment, personalized management should rely on pathogenesis. One promising approach involves identifying biomarkers associated with specific pathogenic pathways. With the advancement of technology, proteomic studies could be a valuable tool to improve knowledge in this area and define valid biomarkers, as they have in other areas of glomerular disease. This work attempts to cover and discuss the main mechanisms of podocyte injury, followed by a review of the recent literature on proteomic biomarker studies in podocytopathies. Most of these studies have been conducted on biofluids, while tissue proteomic studies applied to podocytopathies remain limited. While we recognize the importance of non-invasive biofluid biomarkers, we propose a sequential approach for their development: tissue proteomics could first identify proteins with increased expression that may reflect underlying disease mechanisms; subsequently, the validation of these proteins in urine or plasma could pave the way to a diagnostic and prognostic biomarker-based approach. Full article

A20/Tnfaip3, an early NF-κB response gene and key negative regulator of NF-κB signaling, suppresses proinflammatory responses. Its ubiquitinase and deubiquitinase activities mediate proteasomal degradation within the NF-κB pathway. This study investigated the involvement of A20 signaling alterations in podocytes in the development of kidney injury. The phenotypes of A20Δpodocyte (podocyte-specific knockout of A20) mice were compared with those of control mice at 6 months of age to identify spontaneous changes in kidney function. A20Δpodocyte mice presented elevated serum urea nitrogen and creatinine levels, along with increased accumulation of inflammatory cells—neutrophils and macrophages—within the glomeruli. Additionally, A20Δpodocyte mice displayed significant podocyte loss. Ultrastructural analysis of A20 podocyte-knockout mouse glomeruli revealed hypocellularity of the glomerular tuft, expansion of the extracellular matrix, podocytopenia associated with foot process effacement, karyopyknosis, micronuclei, and podocyte detachment. In addition to podocyte death, we also observed damage to intracapillary endothelial cells with vacuolation of the cytoplasm and condensation of nuclear chromatin. A20 expression downregulation and CRISPR-Cas9 genome editing targeting A20 in a podocyte cell line confirmed these findings in vitro, highlighting the significant contribution of A20 activity in podocytes to glomerular injury pathogenesis. Finally, we analyzed TNFAIP3 transcription levels alongside genes involved in apoptosis, anoikis, NF-κB regulation, and cell attachment in glomerular and tubular compartments of kidney biopsies of patients with various renal diseases. Full article